Amino acids are quaternary compounds of carbon, hydrogen, oxygen and nitrogen. They are the primary building blocks of proteins and are important for protein synthesis, metabolic pathways, gene expression and cell signal transduction regulation.
Each amino acid molecule has two functional groups: an amine group (-NH3+) and a carboxylic acid group (-COO-). They have a unique side chain called R, which can be one of many different types of molecules including hydrogen, sulfhydral groups and amide groups.
The properties of amino acids determine their three-dimensional folding patterns and their specific functions. For example, phenylalanine is hydrophobic and tends to be buried within protein interiors or exposed to lipids along the transmembrane segments of integral membrane proteins.
The number of carbon atoms on an amino acid's side chain influences its hydrophobicity. The aliphatic amino acids are alanine, glycine, isoleucine, leucine, proline, and valine. They are both hydrophilic and non-polar but less hydrophobic than the five charged amino acids described above.
Several aliphatic amino acids are essential for human health, including alanine, glycine, and isoleucine. They are also used in the production of neurotransmitters, such as serotonin and dopamine.
The other eight amino acids are all nonessential but may be required in certain situations, such as during pregnancy, illness, or when recovering from injury. In these cases, you can take amino acid supplements to meet your needs. For example, you can take arginine supplements to help with muscle growth and energy production when your body isn't making it naturally.
